Field of the Invention
This invention relates to refrigeration appliances, and in particular to enclosures therefor.
Description of the Prior Art
In conventional refrigeration appliance cabinet constructions, an outer metal cabinet is provided having an inner liner which may conventionally be formed of plastic spaced inwardly therefrom to define a space in which is provided suitable insulation. The insulation may be in the form of fiberglass pads and in one improved form, the insulation comprises foamed-in-place insulation. One such foamed-in-place refrigeration apparatus enclosure construction is shown in U.S. Pat. No. 2,962,183, of J. C. Rill, Jr. et al. Such foamed-in-place cabinet constructions are relatively costly as they utilize separate liner elements, relatively costly preparations for the foaming operation, and costly fixtures for accurately retaining the cabinet and liner elements during the foaming operation. The liners are relatively expensive in that they require relatively costly tooling and processing steps, and the cost problems of such conventional foamed-in-place construction are aggravated where a number of different size models must be provided.
One attempted solution to this problem is that shown in U.S. Pat. No. 3,635,536 of Robert Lackey et al, wherein a portable refrigerator is shown as having a low cost cabinet utilizing a foam slab box having integral sides formed of a single sheet of foamed plastic. This patent teaches that if the foamed plastic is formed in a chilled mold process, coating of the inner and outer sides of the sheet may be omitted as the plastic is thusly formed with a thick impervious skin. In the absence of such a molding process, metal vinyl-clad sheets of extremely thin gauge may be utilized as an outer facing material. The box sides are formed from a notched slab which permits folding to the box configuration. The notches comprise cut portions on the inside of the sheet permitting the thick slab to be folded inwardly to form the box sides.